The invention relates to garden equipment, and more particularly to an apparatus suited both to mowing grass and to mulching brush clippings or other organic articles.
An implement for mulching brush clippings, garden trimmings and other cuttings is a very desirable addition to home gardening equipment. Such mulched organic matter is best used by returning it to the soil in the lawn or garden for decay and natural conversion into fertilizer. However, the mulching or shredding of cuttings or other matter can also serve simply to compact it, thereby facilitating its disposal. The gardening equipment of most homes does not include a mulcher, primarily because of expense, storage space required for the additional implement, and inconvenience in transporting such an implement to the location of the work.
It has been recognized that the power of a rotary type lawn mower can be utilized for mulching of organic matter, particularly cut blades of grass and leaves from the lawn itself. See, for example, U.S. Pat. Nos. 3,157,015 and 3,531,923, showing separate mowing and mulching blades on the shaft of a rotary mower. U.S. Pat. Nos. 2,701,992 and 3,836,024 show mower blades which coact with fixed backup supports adjacent to the path of blade travel, for severing, but not for mulching or shredding, organic articles.
The mounting of a material hopper on a rotary lawn mower has also been suggested, as in U.S. Pat. Nos. 2,847,224, 3,100,371 and 2,861,611. The latter patent shows a hopper mounted over an opening in the mower housing for feeding to the mowing blade various organic items such as corn stalks and leaves for cutting and distribution by the blade. However in general, the mower implements in use heretofore have not been capable of efficiently cutting and shredding materials, including relatively heavy brush clippings and other items fed from a hopper, and of delivering the shredded mulch to a collection container external of the mower housing. Those employing blades without any fixed coacting means were inefficient in that articles received in the housing would often be simply thrown around by the blades, inertia being depended upon to hold the items for cutting. Also, such devices utilizing only a single blade could not chop and shred articles into a relatively fine mulch, since an article once fed into the hopper was generally engaged only once or twice by the blade before dropping to the ground below.
Mulching lawn mowers of the prior art, particularly those provided with multiple blades, have been capable of mulching primarily only cut grass and leaves, and have not even included a material feeding hopper above the housing. No prior combined mowing and mulching device was capable of efficiently chopping and shredding a wide variety of types, sizes and toughnesses of articles, or of delivering the finely shredded mulch material into an external collecting container, to the extent of the apparatus of the present invention described below.